PSLE A stationery shop is having a book sale.
The 1st book is at 5% discount.
The 2nd book is at 15% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Xuan and Oscar each bought two books at the sale.
- Xuan's books were priced at $29 and $32. How much less did she pay for the 2nd book than the 1st book?
- Oscar paid a total of $31.10 for his two books. He paid $10.70 less for the 2nd book than for the 1st book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $32 |
100% $29 |
|
Discount |
- 5% |
- 15% |
|
Sale price |
95% |
85% |
? |
(a)
Selling price of the 1st book
= 95% x 32
=
95100 x 32
= $30.40
Selling price of 2nd book
= 85% x 29
=
85100 x 29
= $24.65
Amount that Xuan paid less for the 2nd book than the 1st book
= 30.40 - 24.65
= $5.75
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 15% |
|
Sale price |
95%
|
85%
|
|
Compare 1st book and 2nd book |
1 u + $10.70 |
1 u |
$31.10 |
(b)
Sale price of the 1st book = 1 u + 10.70
Sale price of the 2nd book = 1 u
Total amount that Oscar paid
= 1 u + 10.70 + 1 u
= 2 u + 10.70
2 u + 10.70 = 31.10
2 u = 31.10 - 10.70
2 u = 20.40
1 u = 20.40 ÷ 2 = 10.20
Sale price of the 1st book
= 1 u + 10.70
= $20.90
95% of the price = $20.90
100% of the price =
20.9095 x 100 = $22
Selling price of the 1st book before discount = $22
Answer(s): (a) $5.75; (b) $22